Thumb sucking in children may cause problems with their teeth later on.

A: TRUE

Prolonged thumb sucking may be responsible for many problems with the bite. The constant pressure of the thumb itself can create a gap between the top and bottom teeth in front, a condition called an “open bite.” It also reinforces the habit of using the “tongue thrust” motion in swallowing, where the tongue is positioned between top and bottom teeth. This habit may also block full eruption of the front teeth.

Infants and young children swallow exactly the same way that adults do.

A: FALSE

When they swallow, young children use what is called the “infantile swallowing pattern.” In this method, which begins before their teeth have erupted, the tongue is thrust forward in the mouth, sealing and supporting the lips. In adult swallowing, the tongue touches the roof of the mouth, behind the front teeth. The transition from the infantile method usually happens naturally, by around age 4.

Most open bites result from the habit of positioning the tongue too far forward.

A: TRUE

Failure to transition between the infantile and adult swallowing pattern is believed to be the cause of most open bites. The tongue's position alone may prevent the front teeth from fully developing. Allowing the thumb to rest between the teeth has the same effect — and it can also push the front teeth forward. Other causes of an open bite are skeletal or jaw-related problems.

It is harder to cure open bites caused by thumb sucking or bad tongue position than those from other causes.

A: FALSE

Open bites that are caused by skeletal factors (patterns of bone growth, etc) are often difficult to resolve. Those caused by dental factors (tongue position, tooth eruption, etc) are generally easier to fix. However, the pressure exerted by the thumb over a long period of time can influence bone growth in the jaw.

There is a dental appliance that can help discourage thumb sucking.

A: TRUE

A thin metal “tongue crib” placed behind upper and lower incisors discourages the thumb-sucking habit. It also helps to “re-train” the tongue, keeping it from going between upper and lower teeth. To successfully treat an open bite caused by dental factors, and to prevent its reoccurrence, it is essential to eliminate the unhelpful habits of both the thumb and the tongue.